Re: M3UA and SUA recommendations
Stanislav Ivanovich <[email protected]>
| Newsgroups | gmane.ietf.sigtran |
|---|---|
| Message-ID | <[email protected]> |
Siu Chai, Look below for my comments. / Stanislav Siu Chai Tho <[email protected]> wrote: Stanislav, Stanislav Ivanovich <[email protected]> wrote: You should not understand all the parts of any RFC paper as normative ones if they do not affect behavior on the external protocol. [Siu Chai Tho] No layer will ever be visible externally, it is essentially an abstract definition concept. This is not unique for SIGTRAN but goes for all protocol layers (such as defined in RFC 1122 or ITU-T SS7 specifications). Layering is a architectural design pattern and thus only applicable to implementations. Nevertheless it's an important architectural choice to choose layers. [...] [Stanislav Ivanovich] Nonsense! Layering or not layering is certainly not visible on the external xxUA protocols since it is implementation matter. For example I have two M3UA ASP implementations: 1) One applies layered approach where traffic control appplication + supporting user part functions are kept intact while all the AS concepts are put within a layer called "M3UA ASP" which is managed separately. 2) In the second non-layered approach I decide to make modifications to 3 SW components of traffic control application + 2 SW components of user part functions because by looking into product manaulas, descriptions, sequence diagrams (i.e. not in xxUA specifications but instead in my implementation documents) I found that it is easier to make these modifications than to introduce a separate "M3UA ASP" layer which shall be separately controlled by its own management (commands)... However both (!) of my ASP implementations when connected to SGP behave strictly 100% in compliance with ASP-SGP protocol as defined in M3UA specification! So if I connect one of my M3UA ASP implementations to your M3UA SGP implementation (which might be also 100% compliant with ASP-SGP protocol specification) how can your SGP know which ASP implementation I use? Of course it cannot since the difference is externally not visible! Therfore this is not specification (normative) issue but impelemtnation one. If you claim opposite then what is the tool/mechanism used on the external protocol (e.g. message, parameter, parameter value etc...) by which you can tell the difference which ASP implementation I use??? [Stanislav Ivanovich] Why then different process types??! ? Read terminology sections of both SUA and M3UA: "IP Server Process (IPSP) - A process instance of an IP-based application. An IPSP is essentially the same as an ASP, except that it uses SUA in a peer-to-peer fashion." "Signalling Gateway Process (SGP) - A process instance of a Signalling Gateway. It serves as an ac! tive, load-sharing or broadcast process of a Signalling Gateway." Don't you need IPSP and ASP to serve the interface to the MTP/SCCPuser and the SGP to serve the interface to MTP/SCCP ? That in itself is a difference. The difference between ASP and IPSP is as you quoted above, an IPSP can talk to other IPSPs serving MTP/SCCP users. [Stanislav Ivanovich] See my comments above (and the previous ones again). Thank you, Joe Send instant messages to your online friends http://au.messenger.yahoo.com _______________________________________________ Sigtran mailing list [email protected] https://www1.ietf.org/mailman/listinfo/sigtran --------------------------------- Yahoo! Photos Showcase holiday pictures in hardcover Photo Books. You design it and well bind it! _______________________________________________ Sigtran mailing list [email protected] https://www1.ietf.org/mailman/listinfo/sigtran